As the ink-jet printing field develops, improvements in printing characteristics such as edge acuity, optical density, substrate adherence, dry time, resolution, durability, waterfastness, etc., continue to be explored. At the same time, while trying to improve upon these characteristics, fluids of the ink-jet system should also provide long term storage stability and long term reliability without significant equipment corrosion or nozzle clogging. Because all of these goals are difficult to achieve, commercial inks for use in ink-jet printers often represent a compromise in an attempt to achieve at least an adequate response in meeting the above listed objectives.
Various substances have been used to formulate ink-jet inks and other recording solutions in an attempt to meet the above objectives and others. Some of these substances that have been included are pigments and/or dyes to provide color to the image, water and/or water-soluble or miscible organic solvents to provide a liquid composition that functions properly within ink-jet equipment, surfactants of various ionic character to provide decreased surface tension at various liquid interfaces, dispersants for enhancing solubility or dispersion characteristics, and various other solution characteristic modifiers such as viscosity modifiers, pH adjustors, antiseptics, antioxidants, chelating agents, biocides, or the like. These additives can be used to achieve certain printing goals such as those related to ink flow, surface tension, scratch resistance, etc. However, some additives, though they may work well in certain ink formulations, can cause bioaccumulation of hazardous materials in fish and mammals, and thus, are not particularly environmentally friendly.